本文利用分子動力學模擬(Molecular Dynamics Simulation)以及原子力顯微鏡(Atomic Force Microscope)實驗來探討溫度對奈米尺度下接觸物體間黏滯現象的影響及其物理行為。在分子動力學模擬中，採用Morse勢能函數來描述金原子間的作用力，系統模型利用約一萬顆的金(Au)原子以面心立方(FCC)的排列方式，建構成原子力顯微鏡中探針與基材的幾何形貌，其中角錐形探針是由3632顆金原子所組成，立方體基材則是由7168顆金原子所組成。本研究發現，溫度會對原子級的跳躍接觸（Jump-to-contact）現象造成影響，當系統溫度愈高時，此現象越早發生。另外，探針與基材分離時，因黏滯造成的原子遷移產生了頸縮(Necking)現象，緊縮的高度與溫度成正比。在緊縮現象斷裂後，接著即於基材表面形成島狀結構(Island structure)，此奈米結構（頸縮與島狀結構）尺寸與溫度的高低為正相關；黏滯力的大小是隨著溫度升高而下降。研究結果也顯示，由於黏滯現象的作用，探針與基板間機械式的接觸和奈米線及奈米點的形成有很大的關連性。
實驗部份利用表面鍍金的矽探針與基材，在不同環境溫度下來進行力量曲線(Force curve)的繪製與黏滯力量的量測。由實驗結果發現，黏滯力與模擬結果的趨勢相符隨環境溫度升高而降低。比較古典黏滯理論所求得之黏滯力大小與實驗結果有很大的差異，此差異主要說明了連體理論對於介觀尺寸物體的不適用。所以使用古典理論來估算奈米尺度下接觸物體間的物理行為是不適合的。

This thesis presented an investigation of the temperature effect on adhesion phenomenon and its physical behavior between contact bodies in the nano-scale by using molecular dynamics simulation and experiments. In the molecular dynamics simulation, the Morse potential function was employed to simulate the intermolecular forces between atoms. The system model is arranged in order according to face-centered cubic (FCC) structure and constructed as the AFM tip and substrate system, which consists of about 10800 Au atoms. The tip with the pyramidal shape was formed from 3632 Au atoms, while the substrate with the cuboid shape was from 7168 Au atoms. The simulation results reveal that the system temperature affects the atomistic jump-to-contact behavior. The higher the system temperature is, the earlier the contact occurs. In addition, owing to the atom migrations caused by adhesion, an extended neck is gradually formed upon the retraction of the tip from contact and the neck height is positively correlated to the system temperature. After the neck breaks, an island shape structure is formed on the substrate and the size of the structure also has a positive correlation with the system temperature. Adhesion force is calculated during the tip ascending period, the results also show the adhesion force is decreasing with the increase of system temperature.
In the experimental study, the Au-coated Si tip and substrate are utilized to plot the force curve at different ambient temperature. The adhesion force is measured from the force curve. The trends of adhesion force agree with the results of simulation, it demonstrated that the adhesion force for the Au tip and substrate is decreasing with increasing temperature. By comparing with the adhesion forces estimated from the classical adhesion theories, the experimental results exhibit a huge variance. This variance on the adhesion force may attribute to the applicability of the continuum theory for the mesoscopic bodies. So, using the classical adhesion theories to estimate the physical behavior of the contact bodies in the nano-scale may not be appropriate.

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